Ophthalmic illuminators allow a surgeon to illuminate the interior structure of the eye such as the vitreous and the retina during surgical procedures. For example, an endoscopic ophthalmic illuminator (endo-illuminator) includes an optical fiber within the bore of a cannula. By driving a proximal end of the optical fiber with a suitable light source, light emitted from a distal end of the fiber illuminates the desired portion of the eye during a surgical procedure. Alternatively, a physician may illuminate the eye with fiber optic illumination while using an ophthalmic microscope.
One factor for ophthalmic illumination is the spectral output. In general, biological tissue is a broadband reflector such that white light illumination is preferable. However, there are situations such as the use of dyes or the detection of certain proteins in which a physician will prefer a suitably colored illumination. In general, most conventional white light sources such as a white light LED provide a fixed spectral output. However, the desired spectral output for ophthalmic illumination may vary depending upon numerous factors that are difficult to predict a priori such as: the physical appearance of the retina; the desired illuminance (luminous flux/area) in the operating field, the desired Color Rending Index (CRI) for adequate visualization of the retinal tissue; and the degree of contrast enhancement or color suppression desired during the surgery; Another factor for ophthalmic illumination is the resulting aphakic hazard potential, which is the potential for light-induced photochemical damage to the retina. In general, there is virtually no aphakic hazard at wavelengths longer than 510 nm. The aphakic hazard can thus be virtually eliminated by using only those wavelengths longer than 510 nm. Thus, the desired spectral output for ophthalmic illumination may also vary according to the expected length of the operation and the proximity of the distal end of the illumination probe to the retina.
Accordingly, there is a need in the art for an improved ophthalmic illuminator that adjusts its output spectrum in real time.